The Peak Downs District hosts significant coal deposits. Mining began in the late 1970's with the opening of Gregory coal mine (1979). Employee housing was built in Capella and Emerald. The Oaky Creek coal mine followed in 1983. The township of Tieri was constructed to house the operational workforce for the latter mine. Longwall underground mining operations commenced at German Creek Southern in December 1989 and four more mines were commissioned in the 1990's at Ensham, Crinum, Kestrel and Oaky No. 1.
These coal resources are located in within three coal-bearing sequences that lie in an acuate zone of the Permian-age Bowen Basin. Coal mined from these seams is predominately used as coking coal for steel production.
Ongoing exploration continues to identify and upgrade the status of coal resources.
Examples of coal resources:
The Gregory-Crinum coal mine is located 34km east of Capella but operations have ceased. Coal resources were largely within the 3.5 m thick Lilyvale Seam of the German Creek Formation. The Gregory-Crinum operation included three underground mines (Crinum, Crinum East and Crinum North) and one open-cut mine (Gregory). The underground mines used longwall retreat extraction methods, while the open cut used draglines for overburden removal.
The Kestrel/Kestrel West mining is located 39km east of Capella and contains coking and thermal coal suitable for underground mining. The 3m thick, German Creek Seam within the German Creek Formation is the economic seam. The Kestrel operation involves underground mining using longwall units.
The Ensham coal mine is located about 60 km kilometres southeast of Capella. Coal resources are mainly in the Aries and Castor Seams within the Rangal Coal Measures. Both open cut and underground extraction methods are used